Circuit interrupters



Jan. 1, 1963 w. M. LEEDS 3,071,671

CIRCUIT INTERRUPTERS Filed July 22, 1959 L| 3 g 4 A Q L2 l4 l4 l4 I l4 EOperating Mechanism :3 l3 1:1 7)

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WITNESSES INVENTOR m Winthrop M. Leeds United States Patent Ofifice3,071,671 Patented Jan. 1, 1963 3,071,671 CIRCUIT INTERRUPTERS WinthropM. Leeds, Forest Hills, Pa, assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of Pennsylvania FiledJuly 22, 1959, Ser. No. 828,861 13 Claims. (ill. 200-148) This inventionrelates to circuit interrupters in general, and more particularly toimproved arc-extinguishing structures and mounting arrangementstherefor. The invention has particular applicability for very high-voltage service, such as 230 or 345 kv. and above.

A general object of the present invention is to provide an improvedcircuit-interrupting arrangement particularly suitable for high-voltageapplication, and in which a number of unit-type interrupting structuresmay be employed readily in series circuit.

A more specific object of the present invention is to provide animproved unit-type, multiple-break, circuitinterrupting assemblageoperable to effectively interrupt the connected circuit.

Another object of the invention is to provide an improvedarc-extinguishing assemblage involving a pair of upstanding, generallytubular, interrupting structures with improved operating means forsimultaneously effecting their opening and closing operations.

In United States patent application filed January 13, 1959, Serial No.786,587, entitled Circuit Interrupters by Winthrop M. Leeds and Harry J.Lin'gal, and assigned to the assignee of the instant application, thereis disclosed and claimed a generally tubular interrupting structureemploying a rotatable contact blade, which electrically bridges a pairof relatively stationary contact structures. One end of the rotatablecontact blade separates from its associated relatively stationarycontact structure to draw a pressure-generating arc. The other end ofthe rotatable contact blade simultaneously separates from its associatedrelatively stationary contact structure to draw an interrupting arc.Fluid under pressure, generated at the pressure-generating arc, isforced generally longitudinally along the generally tubular interruptingstructure and out one open end thereof adjacent the interrupting are toeffect the extinction thereof.

It is another object of the present invention to improve upon theinterrupting structure disclosed in the aforesaid Leeds and Lingalpatent application, particularly adapting it for multiple-unit, 'highvoltage service, such as the 230 or 345 kv. service voltage noted above.

Still a further object of the present invention it to provide amultiple-break interrupting assemblage involving a pair of the aforesaidgenerally tubular interrupting structures, in which the metal casingsserve in a conducting capacity, so that only a single terminal bushingneed be associated with each generally tubular interrupting structure.

Yet a further object of the present invention is to employ one or moreserially related upstanding interrupting assemblages, supported up inthe air upon an insulating support, in which a single operatingmechanism, disposed at ground potential, may be employed andinterconnected to the one or more interrupting assemblages tosimultaneously effect their opening and closing operations.

Further objects and advantages will readily become apparent upon readingthe following specification, taken in conjunction with the drawings, inwhich:

FIGURE 1 illustrates, in side elevation, and somewhat diagrammatically,a multiple-unit, interrupting assemblage, particularly adapted forhigh-voltage service, such as 345 kv. and above; and

FIG. 2 is a considerably enlarged, side elevational view, partially invertical section, of one of the unit-type, arc extinguishing assemblagesemployed in the interrupting structure of FIG. 1, the contact structurebeing illustrated in the fully open-circuit position.

Referring to the drawing, and more particularly to FIG. 1 thereof, thereference numeral 1 generally designates a multiple-unit,circuit-interrupting structure suitable for very high-voltage service,such as, for example, 230 or 345 kv. and above. Generally, it will benoted that there are employed a plurality of serially relatedarccxtinguishing assemblages, generally designated by the referencenumeral 2. A transmission line L is connected to the left-hand end or"the left arc-extinguishing assembiage 2.. The right-hand end of theleft-hand arc-extinguishing assemblage is connected by a strap connector3 to a middle arc-extinguishing assemblage 2, which, in turn, isconnected, by a strap connection 4, to the right hand arc-extinguishingassemblage 2. The other line connection L is connected, as shown, to theright-hand end of the right-hand arc-extinguishing assemblage 2.

Preferably a single operating mechanism, disposed within an operatingmechanism compartment 6, at ground potential, is employed to eifect thesimultaneous operation of all three arc-extinguishing assemblages 2. Asshown, a weatherproof metallic tubular casing 7 encloses a rotatableoperating shaft, not shown, which is connected by linkage, not shown,within the base structures 8, 9, 10, of the arc-extinguishingassemblages 2 to efiect vertical reciprocal motion of an insulatingoperating rod 11 (FIG. 2), which is associated with eacharcextinguishing assemblage 2.

As illustrated in PEG. 1, it will be noted that each arcextinguishingassemblage 2 is supported at the upper end of an insulating cylindricalcolumn 13, which may be formed from a suitable strong insulatingmaterial, such as ceramic, or the like. The insulating operating rod 11,as shown in FIG. 2, extends upwardly interiorly Within each hollowporcelain column 13.

FIG. 2 more clearly shows the internal construction of eacharc-extinguishing assemblage 2. With reference to this figure, it willbe observed that, generally, each arcextinguishing assemblage 2 includesa spaced pair of generally tubular interrupting structures 14 supportedupon a line conducting support plate 15, the latter being secured by amounting flange ring 16 to the upper extremity of the hollow porcelaincolumn 13. As shown, a terminal bushing 18 includes a porcelainweatherproof casing 19, which surrounds a tubular insulating sleeve 20.The in sulating sleeve 20 may either be a molded insulating dielectricbody, or it may include spaced foil layers embedded in insulatingmaterial to provied a capacitance means associated with the terminalbushing 18, as well known by those skilled in the art. A conductor stud2 1 extends longitudinally through the terminal bushing 18. At its outerextremity there is provided a threaded stud portion 22, adaptable eitherfor connection with a transmission line, such as the line L in FIG. 1,or it is adaptable for the connection to a strap connector, such as thestrap connectors 3, 4 of FIG. 1.

The inner end of the conductor stud 21 is electrically and mechanicallyconnected to a relatively stationary contact structure, generallydesignated by the reference numeral 23 in FIG. 2. The relativelystationary contact structure 23 not only serves as a contact structure,as hereinafter described, but also the relatively stationary contactstructure 23 cooperates with the conductor stud 21 to detachably supporta generally tubular interrupting unit 24 fixedly into position.

Cooperating with the relatively stationary contact structure 23 to drawan interrupting are 25 is the upper end 26 of a rotatable contact blade,generally designated by the is reference numeral 27. Although FIG. 2, asmentioned, illustrates the contact structure in the fully open-circuitposition, for purposes of illustration, the interrupting are has beenindicated.

The lower end 28 of the rotatable contact blade 27 constitutes a movablepressure-generating contact, which cooperates with a second relativelystationary contact structure 29, to draw a pressure-generating are 30.The pressure-generating are 30, established between contacts 28, 29,generates pressure within the arc-extinguishing medium 31 disposedinteriorly within the live metallic casing 32, and forces this medium,under pressure, upwardly in the direction, indicated by the arrows 33,and out the open upper end 34 of the insulating casing 35 of theinterrupting unit 24. To assist in the interruption of the interruptingarc 25, there is preferably provided an orifice sleeve 36 and a splitterplate 37. The present invention, however, is not limited to anyparticular type of interrupting structure disposed at the upper end ofthe insulating casing 35 of the interrupting unit 24, since other typesof interrupting structures, than the type illustrated in FIG. 2, willobviously suggest themselves to those skilled in the art. Merely forpurposes of illustration is the simple orifice construction 36 and thesplitter arrangement 37 employed.

As shown in FIG. 2, the rotatable contact blade 27 is pivotallysupported about a stationary shaft 38, which is journaled indiametrically disposed apertures provided in the insulating casing 35.To efiect rotatable motion of the contact blade 27, there is provided anactuating link 39 of insulating material. Preferably the actuating link39 is of composite construction, including a bifurcated metallic rod-end39a and an insulation portion 39b. The bifurcated metallic rod-endportion 39a of the link 39 is pivotally connected, as at 40, to therota-table contact blade 27 and effects the rotation thereof about thepivot shaft 38.

The insulation portion 39b of link 39 has a threaded connection, as at41, to the bifurcated rod-end portion 39a. In addition, the insulatingrod portion 39b is pivotally connected, as at 42, to a bell-crank 43,which is stationarily pivoted at 44. The stationary pivot shaft 44could, of course, be journaled within interiorly disposed boredbossportions, not shown, afiixed to the inner wall of a metallic tubularmechanism housing 45, which inter-connects the metallic tanks 32 of thetwo tubular interrupting structures 14.

There is, of course, a stationarily mounted bell-crank 43 associatedwith each interrupting unit 24. As shown,

the arms 46 of the two bell-cranks 43 are pivotally connected, as at 47,to links 48. The lower ends of links 48 are pivotally connected, as at49, to a metallic operating rod enlargement 50, which is secured, as bybrazing, to the lower end of a metallic bellows 51. The operating rodenlargement 50 is disposed at the upper end of a metallic portion 52,which is threadedly secured, as at 53, to the lower insulating portion54 of the operating rod 11.

A spring seat 55 is fixedly secured to the metallic end 52 of theoperating rod 11, and serves as the lower seat for an acceleratingcompression spring 56, the latter being disposed interiorly within anupstanding metallic spring casing 57. The upper end of the acceleratingspring 56 seats against a radially inwardly extending flange portion 58secured, as by welding at 59, to the inner wall of the metallic springcasing 57.

It will be apparent that the metallic bellows 51 separates, in agas-tight manner, the region 60 within mechanism housing 45 and the twosteel tanks 32 from a region 61 interiorly of spring casing 57. In otherwords, it is desirable to retain the arc-extinguishing medium 31,preferably under pressure, within the casings 32. A curvedinterconnecting conduit 63 interconnects the lower ends of the steeltanks 32 passing around the spring casing 57. Thus, where liquefiedsulfur hexafluoride, or liquefied selenium hexafluoride are used, asmore fully de- 4 scribed hereinafter, the liquid level 64 will be thesame within both tanks 32.

Detachably closing the upper ends of both steel tanks 32 is a removablecover plate 65, secured by bolts 66 to a flange portion '67, which maybe welded to the upper end of each tank 32. To facilitate the removal ofeach arc-extinguishing unit 24 upwardly out of the open end of the tank32, following removal of upper closure cap 65, there is also provided adisconnecting contact structure 68 disposed at the lower end of the tank32. This disconnecting contact structure 68 includes a rodshapeddisconnecting contact 69 afiixed to the relatively stationary contactstructure 29, and removable therewith when the interrupting unit 24 isbodily lifted upwardly out of the open upper end of the tank 32 duringmaintenance operations.

Cooperating with the rod-shaped disconnecting contact 69 is a cluster ofrelatively stationary finger-type disconnecting contacts 70, suitablyafiixed to the conducting support plate 15. As a result, followingremoval of upper closure cap 65, by unscrewing the bolted connections66, the interrupting unit 24 may be removed upwardly and out of the tankstructure 32 for inspection or replacement of the contact structures 23,29. In connection with this operation, there also occurs removal of anaccess cover 71, and detachment of the pivotal connection 42. Also aWrench may be inserted through the opening 72 to unscrew the insulatingrod portion 39b from the bifurcated metallic rod-end portion 390 at thethreaded connection 41. It will, therefore, be evident that upwardremoval of the interrupting unit 24 is axially brought about bydisconnecting the linkage and removal of the cover plates 65, 71.

In United States patent application filed September 13, 1957, Serial No.683,760 by Winthrop M. Leeds and Benjamin =P. Baker, and assigned to theassignee of the instant application, there is disclosed and claimed theuse of liquefied gases, such as liquefied sulfur hexafiuoride gas (SP orliquefied selenium hexafiuoride gas (SeF or other liquefied gases,disclosed in this patent application, for use in circuit interrupters asarc-extinguishing mediums.

As mentioned, other arc-extinguishing fluids may be employed, butparticular advantage is obtained by the use of liquefied gases. Althoughliquefied SP has been described as an example of a possible liquefiedgas, in describing the operation of the present structure, it is to beclearly understood that liquefied selenium hcxafluoridc, or any one, ora mixture of two or more, of the liquefied gases enumerated below in thefollowing table may be employed in substitution of liquefied SF Thevarious gases which are suitable in liquid or gaseous form for use inthe interrupter of the type considered, have similar properties andcharacteristics as set out in the following table:

Vapor Dielectric Boiling Pressure, Strength Point t /Sq. in. ComparedGauge at With Air or 20 C. Nitrogen Although the foregoing liquefiedgases may be used to advantage, exceptional and unusual performance isobtained with liquid SP or liquid SeF or mixtures of these two, sincethe gaseous phase of these two fluids are so highly effective in arcinterruption and have high dielectric strength.

As mentioned, while the interrupting construction is useful for anysuitable gas or liquid having good insulating and arc-quenchingproperties, a preferred embodiment Would utilize sulfur hexafluoride (SPFor low interrupting ability it is sufficient to fill the tank with gasat 30 to 60 p.s.i. Higher interrupting ability can be obtained by usingliquid SP and filling to a level above the lower contacts at which thepressure-generating arc is formed. Maximum interrupting ability wouldrequire sufiicient liquid to completely fill the entire interruptingchamber 35 containing both sets of contacts. The vapor pressure abovethe liquid varies from 100 to 500 psi. over a temperature range from F.to 110 F.

The interrupting operation of the arc-extinguishing assemblage 2 of FIG.2 will now be described. In the closed-circuit position of theassemblage 2, not shown, the electrical circuit therethrough includesconnecting stud portion 22, terminal stud 21, relatively stationarycontact structure 23, through conducting blade 27 to relativelystationary contact structure 29. The electrical circuit then extendsthrough disconnecting contact 69, disconnecting fingers 70 to conductingsupport plate 15. The circuit extends through the right-hand,arc-extinguishing unit 24- in a similar manner to the right-handconnecting stud 22 of right-hand terminal bushing 18.

During the opening operation, the operating mechanism, not shown,disposed within mechanism compartment 6 (FIG. 1) is unlatched, tothereby permit the three accelerating compression sprngs 56, associatedwith the three arc-extinguishing assemblages 2 of FIG. 1, to force theinsulating operating rods 11 downwardly. Since the lower ends of all theoperating rods 11 are interconnected within the base supports 8, 9, 10to the rotatable operating shaft extending longitudinally throughweatherproof tubular casing 7, all the contact structures in the circuitinterrupter 1 are simultaneously opened at the same time.

With reference to FIG. 2, within each arc-extinguishing assemblage 2,the downward opening motion of operating rod 11 will effect, through therotation of the bell-cranks 43, inward motion of the two links 39 towardeach other. This will eifect rotation of both rotatable contact blades27 about their pivotal supports 38, to simultaneously establish apressure-generating are 30 and an interrupting arc 25 within eachtubular arc-extinguishing unit 24. As described hereinbefore, thepressure-generating are 30 will generate pressure within the liquidsulfur hexafluoride (SP for example, and will force thisarc-extinguishing medium 31 upwardly in the direction indicated by thearrows 33, and out through the restricted orifice 73 associated with theorifice sleeve 36. The insulating splitter plate 37 will, of course,assist in the interrupting of the interrupting are 25. Interruptionquickly occurs after only a short break distance, say of 1 7 inches,as'described in the aforesaid Leeds and Lingal patent application. Thecircuit will consequently be interrupted, the several contact blades 27cooperating with the relatively stationary contact structures 23, 29 toprovide the requisite isolating gap distances.

' Where a number of unit type, arc-extinguishing assemblages 2 areemployed in series manner, as shown in FIG. 1, for high-voltage service,say 345 kv. or higher, it will be obvious to those skilled in the artthat certain voltage-distributing arrangements will be desired to evenlydistribute the voltage between the several arc-extinguishing assemblages2. Various voltage graduation schemes are known by those skilled in theart. For example, one such scheme, which may be employed, is that setforth in United States Patent 2,748,226, issued May 29, 1956, to John B.MacNeill and Benjamin P. Baker. Other possible arrangements may beemployed.

Circuit interrupters designed for very high-voltage service, such as 230or 345 kv. and above, for example, are most economically constructed andtested when a multibreak assembly can be made using duplicateinterrupting in part, with a means of adapting the dead-tank, liquidsulfur hexafluoride interrupter, such as set out in the aforesaid Leedsand Lingal patent application, so as to be suitable as a multi-break,high voltage circuit interrupter incorporating live metallic tanks 32.

As illustrated in FIG. 2, only one bushing 18 per tank 32 is required,since the circuit between pairs of interrupters 24 is completed throughthe disconnecting contacts 68 and the live tanks 32.

The interrupters 24 may be readily removed by taking off the main covers65 and the middle access cover 71 to disconnect the links 39, loosen theterminal stud 21 and lift up the interrupters 24 and contacts 23, 29upwardly out of the open upper ends of the tanks 32.

Assuming, for example, that the six interrupting units 24 employed inthe circuit interrupter 1 of FIG. 1 are employed for 345 kv. service, itwill be apparent that due to the use of live tanks 32, only 69 kv.terminal bushings 18 need be employed in connection with thearc-extinguishing assemblage 2.

It will be noted that the two live tanks 32 and the tubular mechanismhousing 45 constitute generally an H-shaped metallic tank means, whichis at line potential in the closed circuit position of the interrupter.The operating rod means 39 extends through the horizontal leg 45 of theH-shaped tank means to effect simultaneous operation of the pair ofseparable contact structures.

Although there has been illustrated and described a particulararc-extinguishing assemblage 2, and showing its multiple series use, asindicated diagrammatically in FIG. 1, it is to be clearly understoodthat the same was merely for the purpose of illustration, and thatchanges and modifications may readily be made therein by those skilledin the art without departing from the spirit and scope of the invention.

I claim as my invention:

1. A circuit interrupter for high-voltage service including a pluralityof spaced upstanding arc-extinguishing assemblages, only a singleupstanding insulating hollow column for supporting eacharc-extinguishing assemblage up in the air above ground potential, anoperating mechanism at ground potential, an insulating operating rodextending interiorly upwardly within each hollow insulating column,contact structure associated with each arc-extinguishing assemblagewhich is operated by the respective insulating operating rod, saidcontact structure including a serially related pair of rotatable contactblades and four serially related stationary contacts, crank means forsimultaneously actuating said rotatable contact blades, and an operatingshaft extending between the hollow insulating columns connected to theseveral insulating operating rods and actuated by said operatingmechanism.

2. A circuit interrupter including an H-shaped arcextinguishingassemblage mounted up in the air above ground potential, the H-shapedarc-extinguishing assemblage including a pair of generally upstandinginterrupting structures and a live conducting support plate electricallyinterconnecting the two interrupting structures in series, eachinterrupting structure including a live metallic tank adaptable forwithstanding considerable internal pressure, separable contact structuredisposed within each live metallic tank, a terminal bushing extendinglaterally through the side wall of each metallic tank and connected tothe separable contact structure disposed therein, and operating meansdisposed between the spaced metallic tanks in the horizontal portion ofthe H-shaped assemblage and connected to the separable contactstructures to effect their simultaneous operation.

3. Circuit interrupting means including a spaced pair of metallic tanks,a pair of terminal bushings extending through the side walls of thespaced pair of metallic tanks, a removable arc-extinguishing unitsuspended within each metallic tank from the interior end of therespective terminal bushing, a live supporting conducting plate closingthe ends of the spaced metallic tanks and having a pair of disconnectingcontact structures thereon, one disconnecting contact structure beingdisposed within each metallic tank, and each arc-extinguishing unithaving a disconnecting contact aifixed thereto and removable therewithwhich cooperates with one of said disconnecting contact structures.

4. Circuit interrupting means including a spaced pair of metallic tanks,a tubular mechanism housing interconnecting the spaced pair of metallictanks constituting thereby a generally H-shaped structure, a pair ofterminal bushings extending through the side walls of the spaced pair ofmetallic tanks, a removable arc-extinguishing unit suspended within eachmetallic tank from the interior end of the respective terminal bushing,separable contact means associated with each arc-extinguishing unit,operating rod means extending through said tubular mechanism housing foreffecting the separation of the separable contact means associated witheach arc-extinguishing unit, a live supporting conducting plate closingthe ends of the spaced metallic tanks and having a pair of disconnectingcontact structures thereon, one disconnecting contact structure beingdisposed within each metallic tank, and each arc-extinguishing unithaving a disconnecting contact affixed thereto and removable therewithwhich cooperates with one of said disconnecting contact structures 5.Circuit interrupting means including a spaced pair of metallic tanks, atubular mechanism housing interconnecting the spaced pair of metallictanks constituting thereby a generally H-shaped structure, a pair ofterminal bushings extending through the side walls of the spaced pair ofmetallic tanks, a removable arc-extinguishing unit suspended within eachmetallic tank from the interior end of the respective terminal bushing,separable contact means including a rotatable contact blade associatedwith each arc-extinguishing unit, operating rod means extending throughsaid tubular mechanism housing for effecting the rotation of saidrotatable contact blade associated with each arc-extinguishing unit, asupporting conducting plate closing the ends of the spaced metallictanks and having a pair of disconnecting contact structures thereon, onedisconnecting contact structure being disposed within each metallictank, and each arc-extinguishing unit having a disconnecting contactafiixed thereto and removable therewith which cooperates with one ofsaid disconnecting contact structures.

6. A circuit interrupter including live H-shaped metallic tank means, apair of terminal bushings extending laterally into said live H-shapedmetallic tank means, a pair of removable arc-extinguishing unitsremovably assoc1ated with the interior ends of the pair of terminalbushings, a conducting support plate closing one end of said liveH-shaped metallic tank means and electrically interconnecting the twoarc-extinguishing units, and detachable cover means at the other end ofthe live metallic tank means.

7. A high-voltage, fluid-blast circuit interrupter includng one or moreserially arranged arc-extinguishing assemblages, a hollow insulatorcolumn for supporting each arcextinguishing assemblage up in the air asafe distance from ground potential, each arc-extinguishing assemblageincluding live metallic tank means enclosing a serially related pair ofarc-extinguishing units of the fluid-blast type, only a single pair ofterminal bushings extending through said metallic tank means, eacharc-extinguishing unit including an insulating tube open at one end andclosed at the other end, a pair of spaced relatively stationary contactstructures disposed along the wall of each insulating tube, a rotatablebridging contact blade pivotally mounted in each insulating tube andelectrically interconnecting the two relatively stationary contactstructures associated with :each insulating tube, the end of the contactblade adjacent the closed end of the tube separating (J from therelatively stationary contact structure at the closed end of the tube toestablish a pressure-generating arc adjacent the closed end of the tube,the other end of said contact blade drawing an interrupting arc adjacentthe opcn end of the insulating tube, and fluid under pressure blastingout of the open end of each tube to extinguish the interrupting aredrawn adjacent thereto.

8. A high-voltage, fluid-blast circuit interrupter including one or moreserially arranged arc-extinguishing assemblages, a hollow insulatorcolumn for supporting each arc-extinguishing assemblage up in the air asafe distance from ground potential, each arc-extinguishing assemblageincluding live metallic tank means enclosing a serially related pair ofarc-extinguishing units of the fluid-blast type, only a single pair ofterminal bushings extending through said metal-lic tank means, eacharc-extinguishing unit including an insulating tube open at one end andclosed at the other end, a pair of spaced relatively stationary contactstructures disposed along the walls of each insulating tube, a rotatablebridging contact blade pivotally mounted in each insulating tube andelectric-ally interconnecting the two relatively stationary contactstructures associated with each insulating tube, the end of the contactblade adjacent the closed end of the tube separating from the relativelystationary contact structure at. the closed end of the tube to establisha pressuregenerating are adjacent the closed end of the tube, the otherend of said contact blade drawing an interrupting are adjacent the openend of the insulating tube, fluid under pressure blasting out of theopen end of each tube to extinguish the interrupting are drawn adjacentthereto, and a conducting support plate for supporting said tank meansand electrically interconnecting the two arcextinguishing units withineach tank means.

9. A high-voltage, iluid b'last circuit interrupter including one ormore serially arranged arc-extinguishing assemblages, a hollow insulatorcolumn for supporting each arc-extinguishing assemblage up in the air asafe distance from ground potential, each arc-extinguishing assemblageincluding live metallic tank means enclosing a serially related pair ofarc-extinguishing units of the fluid-blast type, only a single pair ofterminal bushings extending through said metallic tank means, eacharc-extinguishing unit including an insulating tube open at one end andclosed at the other end, a pair of spaced relatively stationary contactstructures disposed along the walls of each insulating tube, a rotatablebridging contact blade pivotally mounted in each insulating tube andelectrically interconnecting the two relatively stationary contactstructures associated with each insulating tube, the end of the contactblade adjacent the closed end of the tube separating from the relativelystationary contact structure at the closed end of the tube to establisha pressuregenerating'arc adjacent the closed end of the tube, the otherend of said contact blade drawing an interrupting are adjacent the openend of the insulating tube, fluid under pressure blasting out of theopen end of each tube to extinguish the interrupting are drawn adjacentthereto, a conducting support plate for supporting said tank means andelectrically interconnecting the two arc-extinguishing units within eachtank means, removable cover means for said tank means, and adisconnecting contact structure for electrically interconnecting eacharcextinguishing unit with said conducting support plate.

10. A circuit interrupter including an H-shaped metallic tank means atline potential, insulating column means for supporting said H-shapedmetallic tank means at line potential up in the air a safe distance fromground potential, a pair of serially related arc-extinguishing unitsdisposed within said H-shaped metallic tank means, a pair of terminalbushings extending through the side walls of the H-shaped tank means,separable contact means associated with each arc-extinguishing unit, andoperating rod means extending through the horizontal leg of the H-shapedtank means to efiect simultaneous operation of both separable contactmeans.

11. A high-voltage circuit interrupter including a spaced pair ofgenerally tubular interrupting structures, supporting structure, aconducting plate means supported by said supporting structure and havinga spaced pair of relatively stationary disconnecting contacts associatedtherewith, a removable arc-extinguishing unit disposed within eachgenerally tubular interrupting structure and having a movabledisconnecting contact associated therewith for cooperation with therespective relatively stationary disconnecting contact, said conductingplate means electrically interconnecting the two arc-extinguishing unitsin series, cover means associated with each generally tubularinterrupting structure adapted for removal therewith, whereby uponremoval of said cover means from each of said generally tubularinterrupting structures the respective removable arc-extinguishing unitmay be removed causing thereby disengagement of the respective movabledisconnecting contact from the respective relatively stationarydisconnecting contact.

12. A high-voltage circuit interrupter including a spaced pair ofgenerally tubular interrupting structures, supporting structure, aconducting plate means supported by said supporting structure and havinga spaced pair of relatively stationary disconnecting contacts associatedtherewith, a removable arc-extinguishing unit disposed within eachgenerally tubular interrupting structure and having a movabledisconnecting contact associated therewith for cooperation with therespective relatively stationary disconnecting contact, said conductingplate means electrically interconnecting the two arc-extinguishing unitsin series, terminal means extending interiorly within each generallytubular interrupting structure and assisting in supporting therespective arc-extinguishing unit therein, cover means associated witheach generally tubular interrupting structure adapted for removaltherewith, whereby upon removal of said cover means from each of saidgenerally tubular interrupting structures the respective removablearc-extinguishing unit may be removed causing thereby disengagement ofthe respective movable disconnecting contact from the respectiverelatively stationary disconnecting contact.

13. A high-voltage circuit interrupter including a spaced pair ofgenerally tubular interrupting structure-s, supporting structure, aconducting plate means supported by said supporting structure and havinga spaced pair of relatively stationary disconnecting contacts associatedtherewith a removable arc-extinguishing unit disposed within eachgenerally tubular interrupting structure and having a movabledisconnecting contact associated therewith for cooperation with therespective relatively stationary disconnecting contact, said conductingplate means electrically interconnecting the two arc-extinguishing unitsin series, operating rod means extending between the two generallytubular interrupting structures, terminal stud means extending laterallyoutwardly in opposite directions substantially diametrically of saidoperating rod means, cover means associated with each generally tubularin terrupting structure adapted for removal therewith, whereby uponremoval of said cover means from each of said generaliy tubularinterrupting structures the respective removable arc-extinguishing unitmay be removed causing thereby disengagement of the respective movabledisconnecting contact from the respective relatively stationarydisconnecting contact.

References Cited in the file of this patent UNITED STATES PATENTS1,091,659 Hewlett Mar. 31, 1914 1,324,909 Krantz Dec. 16, 1919 2,100,753Schoficld et a1 Nov. 30, 1937 2,258,376 Clothier et a1 Oct. 7, 19412,454,586 Amer Nov. 23, 1948 2,459,600 Strom Jan. 18, 1949- 2,766,348Forwald Oct. 9, 1956 FOREIGN PATENTS 504,138 Great Britain Apr. 20, 1939535,799 Great Britain Apr. 22, 1941 535,956 Great Britain Apr. 28, 1941605,163 Great Britain July 16, 1948 626,842 Great Britain July 21, 1949732,462 Germany Mar. 3, 1943 852,550 France Oct. 30, 1939 856,014Germany Nov. 17, 1952 1,133,485 France Nov. 19, 1956

1. A CIRCUIT INTERRUPTER FOR HIGH-VOLTAGE SERVICE INCLUDING A PLURALITYOF SPACED UPSTANDING ARC-EXTINGUISHING ASSEMBLAGES, ONLY A SINGLEUPSTANDING INSULATING HOLLOW COLUMN FOR SUPPORTING EACHARC-EXTINGUISHING ASSEMBLAGE UP IN THE AIR ABOVE GROUND POTENTIAL, ANOPERATING MECHANISM AT GROUND POTENTIAL, AN INSULATING OPERATING RODEXTENDING INTERIORLY UPWARDLY WITHIN EACH HOLLOW INSULATING COLUMN,CONTACT STRUCTURE ASSOCIATED WITH EACH ARC-EXTINGUISHING ASSEMBLAGEWHICH IS OPERATED BY THE RESPECTIVE INSULATING OPERATING ROD, SAIDCONTACT STRUCTURE INCLUDING A SERIALLY RELATED PAIR OF ROTATABLE CONTACTBLADES AND FOUR SERIALLY RELATED STATIONARY CONTACTS, CRANK MEANS FORSIMULTANEOUSLY ACTUATING SAID ROTATABLE CONTACT BLADES, AND AN OPERATINGSHAFT EXTENDING BETWEEN THE HOLLOW INSULATING COLUMNS CONNECTED TO THESEVERAL INSULATING OPERATING RODS AND ACTUATED BY SAID OPERATINGMECHANISM.